Sin sot should be given as a token and within one's means.
If In-Laws demand sky high sin sot then they're treating you as Mr. Robert lah.
Getting married is a life long affair so all financial matters must work out properly between husband and wife with common goals otherwise the nightmare begins!
What are needs and what are wants?
Needs are roof over your head, children's expenses, education, insurance, etc.
Wants are motor vehicle, luxury goods, jewelleries, latest electronic gadgets, etc.
If the wife cannot prioritise what is more important then better not get married.